The present invention relates generally to switching regulators for regulating power to semiconductor circuitry, and more particularly to integrated inductors for switching regulators.
A power distribution network in a typical System-on-chip (SoC) used in various mobile devices includes on-chip metallization layers connecting to a package substrate via micro-bumps or copper pillars. Signals from or to the micro-bumps or copper pillars are generally routed within the package using one or more redistribution layers (RDL) to balls of the package that connect to a printed circuit (PCB). This may result in a significant parasitic inductance, which may be a significant limiting factor in the performance of these devices as the higher frequencies and higher currents generate local transient effects which are also referred to as droops due to fast changes in the load currents.
The use of embedded voltage regulators (eVRs), typically switching regulators with inductors, may be useful in reducing or accounting for variations presented by parasitic inductances. Providing inductors for an eVR implementation with a high inductance to resistance value (L/R: inductance [nH] per resistance [mohms]) in a small form factor (current rating per square millimeter) may be challenging, however.